Firstly, users should borrow a license in advance if they anticipate use of Revit remotely. You can borrow a license for up to a month. Afterward, you are required to borrow again if needed (requires connecting to our company network).
In the scenario a user did their due diligence and borrowed a license, but still isn't able to attain the borrowed license (and acts as if a license wasn't borrowed) you'll then want to enable autodesk variables from our shares on the users PC (Need to be connected to our VPN first of course). "\\ladco\shares\software\Autodesk\ADeskEnVarsbyIP.cmd"
After doing that, the user (who borrowed a license previously but isn't able to access the license when remote for some reason) should now be able to access their borrowed license.